This invention relates generally to improvements in apparatus, systems and methods for forming custom-made shoe inserts conforming to a person's feet and/or compensating for defects of the person's feet. More particularly, this invention relates to an improved apparatus for digitizing the contour of the undersurface of a person's foot and to an improved system and method, employing such apparatus, for forming such custom-made shoe inserts.
Apparatus, systems and methods for forming custom-made shoe inserts conforming to a person's feet and/or compensating for defects of the person's feet are disclosed, for example, in U.S. Pat. No. 2,230,143 entitled. METHOD AND APPARATUS FOR MAKING ORTHOPEDIC LIFTS (issued Jan. 28, 1941), in U.S. Pat. No. 4,454,618 entitled SYSTEM AND METHOD FOR FORMING CUSTOM-MADE SHOE INSERT (issued Jun. 19, 1984), and in U.S. Pat. No. 4,510,636 entitled SYSTEM AND METHOD FOR FORMING CUSTOM-MADE SHOE INSERTS (issued Apr. 16, 1985). In accordance with such apparatus, systems and methods a foot impression unit is employed for forming an impression of the undersurface of each foot. The foot impression unit includes a housing for supporting the foot, an array of pins supported by the housing for controlled movement to operative positions in contact with the undersurface of the foot (or a sheet of flexible material disposed between the array of pins and the foot) to form the impression, and a locking mechanism for thereupon locking the pins in place to retain the impression. Additionally, the foot impression unit may include provision for holding a foot with defects, such as pronation (an inward deflection of the foot), supination (an outward deflection of the foot), fallen arches or the like, in a corrected position while forming and retaining an impression corrected for such defects. A pivotally-mounted sensing and shaping unit is either manually or automatically driven laterally and to-and-fro across both the retained impression and an insert blank to mechanically sense the impression and to remove material from the blank in conformance with the sensed impression, thereby forming a custom-made shoe insert from the blank.
Since the custom-made shoe insert is formed with a foot supporting surface substantially conforming to the undersurface of the very foot for which the insert was formed, it provides better and more comfortable foot support than is provided by conventional insoles and standardized shoe inserts. Moreover if the custom-made shoe insert was formed from an impression corrected for foot defects, the custom-made shoe insert will tend to compensate for those defects. However, one disadvantage of the foregoing apparatus, systems and methods is that they have employed more expensive and less portable apparatus than desirable to facilitate their widespread adoption and usage in retail shoe stores, podiatrist's offices, and other such customer or patient service locations of the footware and footcare industries. This disadvantage is at least partly due to the fact that the foot impression unit has typically been combined and employed together with the sensing and shaping unit at each customer or patient service location or has been transported in its entirety from each such location, where an impression is formed and retained, to a central shaping location, where the sensing and shaping unit is used for mechanically sensing the impression retained by the foot impression unit and for shaping an insert blank in conformance with the sensed impression to form the custom-made shoe insert.
The aforementioned U.S. Pat. No. 2,230,143 discloses a foot impression unit that may be employed at each customer or patient service location to provide a manually recorded indication of each formed and retained impression upon a chart. In this foot impression unit at least some of the pins in successive rows of the array of pins have been provided with slots having camming surfaces for cooperating with corresponding camming surfaces of associated indicating elements (passing through those slots) to provide an indication of the displacements of those pins. Once the impression has been formed and retained, the indicating elements associated with each row of those pins are manually operated on a row-by-row basis to permit a set of curves indicative of the displacements of those pins to be manually drawn upon the chart along extended ends of the associated indicating elements. This chart is thereupon delivered to the central shaping location where the pins of another such foot impression unit are reset in accordance with the set of curves recorded on the chart and are locked in place to reform and retain the impression indicated by that set of curves. The sensing and shaping unit is then used to mechanically sense that reformed impression and shape an insert blank in conformance with the sensed reformed impression to form a custom-made shoe insert.
In theory the use of such a foot impression unit would obviate the need for transporting the foot impression unit from each customer or patient service location, where an impression is formed and recorded, to the central shaping location, where the recorded impression is reformed, retained and mechanically sensed to shape the blank and form the custom-made shoe insert. However, in practice one major disadvantage of using such a foot impression unit is the time and effort it would initially take at each customer or patient service location to successively manually draw the required set of curves upon the chart and the additional time and effort it would subsequently take at the central shaping location to manually reset the pins of another such foot impression unit in accordance with that set of curves to reform and retain the indicated impression. Another disadvantage is the unliklihood that the impressions formed, retained and manually recorded as sets of curves by different operators using any number of such foot impression units at any number of customer or patient service locations can be consistently and reliably reformed and retained by another operator using those sets of curves and skill another such foot impression unit at the central shaping location. To achieve any degree of consistency and reliability would require considerable training and skill on the part of every operator, as well as a great deal of precision in the construction of every foot impression unit to insure the required uniformity of operation from unit to unit. Still another disadvantage of using such a foot impression unit is that the required significant modification of the pins and use of cooperating manually-moveable indicating elements adds to the complexity and reduces the pin-packing density of the foot impression unit. This increases both the cost and the bulk of the foot impression unit, while decreasing the resolution and, hence, the quality of the impressions formed by the foot impression unit.
A system and method for forming a custom-made shoe last is disclosed in U.S. Pat. No. 3,696,456 entitled CUSTOM SHOE CONSTRUCTION SYSTEM (issued Oct. 10, 1972). Although not disclosed as being useful for forming custom-made shoe inserts, the last-mentioned system and method do employ the concept of obtaining and recording foot model data at a customer or patient service location and forming the custom-made shoe last from that data at a central shaping location. In accordance with that system and method a foot measuring unit, including three contour measuring blocks, is employed at the customer or patient service location to produce electrical analog signals indicative of the contour of the rear, side and upper surfaces of a person's foot. Each of the contour measuring blocks employs an array of pins concentrically attached to associated movable elements of associated tubular variable capacitors, which are arranged to produce electrical analog signals proportional to the positions of the tips of the pins with respect to fixed portions of the variable capacitors. A converter is also employed at the customer or patient service location to convert these electrical analog signals to digital foot model data and to store that data on a magnetic tape. This magnetic tape is subsequently delivered to the central shaping location where the digital foot model data stored on that magnetic tape and data previously used to produce custom-made shoe lasts and stored on another magnetic tape are initially compared by a computer to determine if a shoe last for a similar foot and desired shoe style has already been formed, thereby obviating the need to form a new shoe last. If a shoe last for a similar foot and desired style has not already been formed, the digital foot model data stored on the first-mentioned magnetic tape and the desired style model data stored on still another magnetic tape are combined by the computer to produce shoe-last information recorded on a punched tape. An automatic machine tool is then controlled by that punched tape to cut a custom-made shoe last from a wood blank in conformance with the recorded shoe-last information.
One disadvantage of the foregoing system and method for forming a custom-made shoe last, besides not being useful for forming a custom-made shoe insert, is that they employ a foot measuring unit for producing electrical analog signals indicative of the contour of the rear, side and upper surfaces of the foot and must therefore also employ a converter to process those analog signals and convert them to recorded digital foot model data. This adds to the cost and the bulk of the apparatus employed at each customer or patient service location to obtain and record such data. Another disadvantage of the foregoing system and method is that they do not provide for on-line modification of the recorded digital foot model data at the customer or patient service location to compensate for defects of the foot visually observed at that location. Another disadvantage of the foregoing system and method is that they do not provide for locking the pins of the foot measuring unit in place to retain an impression of the foot formed by those pins. This precludes a visual inspection of the impression formed by the pins of the foot measuring unit to verify the accuracy of the impression and to help in evaluating and discussing with the customer or patient what modification of the recorded foot model data might be most appropriate to compensate for defects of his or her foot. Still another disadvantage of the fore going system and method is that the attachment of the pins to the moving elements of tubular variable capacitors and the use of such tubular variable capacitors to determine the displacements of the pins adds to the complexity and reduces the pin-packing density of the contour measuring blocks. This increases both the cost and the bulk of the foot measuring unit, while decreasing the resolution and, hence, the quality of the impression formed by the foot impression unit.
An object of the various aspects of the present invention is to provide an improved apparatus, system and method for forming custom-made shoe inserts.
Another object of the various aspects of the present invention is to provide an improved apparatus, system and method, as in the last object, for overcoming the previously-mentioned and other disadvantages of the foregoing prior apparatus, systems and methods.
Another object of the various aspects of the present invention is to provide an improved apparatus, system and method, as in either of the last two objects, for facilitating more widespread adoption and usage of such apparatus, systems and methods and for thereby making custom-made shoe inserts more generally available to the public.
Another object of an aspect of the present invention is to provide an improved apparatus for digitizing the contour of a selected surface, such as the undersurface of a person's foot.
Another object of an aspect of the present invention is to provide less expensive, more portable, easier to use, and more reliable apparatus for digitizing the undersurface of a person's foot.
Another object of an aspect of the present invention is to provide an improved system, employing apparatus as in the last two objects, for forming an impression of the undersurface of a person's foot, scanning the impression to form a digital representation thereof, storing the digital representation, and forming a custom-made shoe insert from an insert blank in accordance with the stored digital representation.
Another object of an aspect of the present invention is to provide an improved system, as in the last object wherein the impression of the undersurface of the person's foot is formed and scanned at a customer or patient service location to form the digital representation of the impression, the digital representation is stored at the customer or patient service location and transmitted or sent to a shaping location, and the custom-made shoe insert is formed from the blank at the shaping location in accordance with the stored digital representation.
Another object of an aspect of the present invention is to provide an improved system, as in the last object, for making use of conventional computer equipment and techniques to control the forming and scanning of the impression of the undersurface of the person's foot, the forming and storing of the digital representation of the impression, the transmitting of the stored digital representation, and the forming of the custom-made shoe insert from the blank in accordance with the stored digital representation.
Another object of an aspect of the present invention is to provide an improved system and method for forming an impression of a person's foot (and, if desired, releasably retaining the impression to permit its inspection and evaluation), scanning the impression to form a digital representation of the impression, storing the digital representation, modifying the stored digital representation to compensate for a defect of the person's foot, and forming a custom-made shoe insert from a blank in conformance with the modified stored digital representation.
These and other objects, which will become apparent from a reading of this specification and an inspection of the accompanying drawings, are accomplished according to the preferred embodiment of the present invention by providing an improved foot impression unit and an improved system and method employing that foot impression unit to form custom-made shoe inserts as hereinafter described. This foot impression unit includes a frame for supporting a person's foot, an array of closely packed pins or gauging elements, an inflatable diaphragm, and a locking mechanism. The gauging elements are movably supported by the frame beneath the foot in spaced independently-guided relationship. Each gauging element includes a pair of permanent magnets disposed in opposing relationship at a predetermined intermediate location along the gauging element. The inflatable diaphragm is supported by the frame beneath the array of gauging elements and is inflated under control of a computer to yieldably urge the gauging elements into contact with the undersurface of the foot, thereby forming an impression of the undersurface of the foot. For purposes of the present invention the gauging elements are considered to be in contact with the undersurface of the foot even though a sheet of flexible material, a stocking, or the like should be disposed between the array of gauging elements and the foot. The locking mechanism is supported by the frame between adjacent rows of the gauging elements and may be operated under control of the computer to releasably lock the gauging elements in place and retain the impression of the undersurface of the foot.
In addition, the foot impression unit includes a sensing mechanism having a printed circuit board and an array of hall-effect sensors each mounted on the printed circuit board adjacent to a corresponding gauging element. The printed circuit board is supported by the frame for movement relative to the array of gauging elements under control of a stepper motor, which is in turn controlled by the computer. As the printed circuit board is stepped from its initial position to its final position and then back to its initial position, the array of hall-effect sensors scans the entire array of gauging elements at each discrete level to which the printed circuit board is stepped to produce digital signals indicative of the positions of the gauging elements. Each hall-effect sensor produces one binary digital signal when the printed circuit board is stepped to the discrete level or levels at which the permanent magnets of the corresponding gauging element are detected and another binary digital signal when the printed circuit board is stepped to every other discrete level. These digital signals are processed by the computer to provide a stored digital representation of the impression of the undersurface of the foot. The computer may be employed for modifying this stored digital representation in accordance with one or more visually-observed or measured defects of the foot to compensate for those defects.
A shaping unit is driven in accordance with the stored digital representation and any modifications thereof to remove material from an insert blank and form a custom-made shoe insert conforming to the under surface of the foot and/or compensating for defects of the foot. The shaping unit may comprise a milling machine having a rotary hemispherical cutter movable along X, Y and Z axes for removing material from the blank in accordance with the stored digital representation and any modifications thereof. This milling machine may be located at the same location as the foot impression unit and may be operated under control of the aforementioned computer, or it may be located at another location and operated under control of another computer. In the latter case, the stored digital representation may be transmitted from the aforementioned computer to the last-mentioned computer by employing conventional computer storage, networking or telecommunications equipment and techniques.